Devilsix, for 13 years I owned a 52 Panel I spent 6 years restoring and 7 years driving it until I sold it last summer.
Seeing your determined to go V8 there are some good things out there to get it done. I used a motor mount kit from Classic Parts that I chose to bolt on and it worked very very well. Using the measurements that came with the kit I was able to put the re-man 305 engine in it and using a BIG distributor I sill had enough room to wrap my hand around it at the firewall.
With minimum fabricating skills you can do the rear tranny mount no problem.
To mount my alternator/AC I used the the mounts for them off an S-10 pickup with the V6 engine and this allowed me to run a serpentine belt. Simply set up if the heads have the holds to bolt it on and most are. This kept things up top and easy to get to. I did run an electric fan that covered the entire radiator and never had a heating problem.
You do have a steering box issue but don't make a big deal out of it. A double D shaft and a Saginaw rebuilt steering box for, say a '76 pickup, works great and there is a kit to mount it that is not to expensive from Classic as well.. I did have to cut a hole in the inner fender as the steering box mounts outside the frame toward the front. Instructions come with the small kit which also includes the steering arm. You can source an Idler arm from a Monte Carlo and from several other GM vehicles without paying the high vendor prices. I happened to have one from a 60 Buick Skylark. OH....my steering box was a power steering box and the power steering pump is available at a parts house...And yes, I used my straight axle. NO problems what so ever.
There are other ways to do the steering using a Toyota box and a few other ways but I found the above to be to my liking.
For headers, go ahead and bite the bullet and buy a set of ram horn headers unless you find a good used set. Don't waste your money on a set of headers either. Waste of money!
I drove my panel for 7 years and included trips to the Stovebolt Homecoming in Md. and also the K.C. reunion in Kansas City Mo. without any problems...........I would highly suggest sway bars both front and back since you'll be going a little faster with the V8. These panels can get a little top heavy. I started out with the original front sway bar but quickly found out I needed the rear one as well on a fast exit off an interstate ramp!!!
With the Malibu rear end you should be just fine. I used my original torque tube housing and used a later model "pumpkin" with a good gear ratio. (3.48) from Yukon gear.
*** I"d suggest running a 400R4 or a 700R4 Automatic if you have bad knees like me. I ran a 700R4, with overdrive, and the panel loved it. Cruise all day long at 70 and run smooth as a cat's purr. On this same note I will say a fellow gave me a steering column off a '68 pickup which I used since it was slender, had turn signals and the automatic gear selector. It was free to me and it bolted in with very very little problem. The linkage from the column to the tranny is available at most any decent hot rod shop and is not expensive and works like a champ.
Good luck. But remember, its your vehicle...do it the way you want it so you'll be happy when its finished.
Last edited by Achipmunk; 03/18/2021 12:51 AM. Reason: additional info